1. Field of the Invention
The present invention relates generally to immunology and more specifically to immune responses and diseases involving chronic inflammation.
2. Background Information
Molecular pathways of normal hematopoietic cell differentiation, as well as the mechanisms by which oncogenes disrupt this process, remain poorly understood. In normal hematopoietic progenitor cells, a program of specific gene expression orchestrates commitment and differentiation of mature cells to multiple different lineages. In acute leukemias, however, oncoproteins interfere with this genetic program, resulting in the unregulated proliferation of cells that no longer retain the capacity to differentiate normally. In acute myeloid leukemias (AMLs) many known myeloid oncoproteins can block the differentiation of normal progenitors cultured in vitro in the presence of granulocyte-macrophage colony stimulating factor (GM-CSF) or interleukin-3 (IL-3). However, neither the genetic events that underlie normal hematopoietic cell differentiation nor the mechanism through which leukemic oncoproteins interfere with the execution of the program of lineage differentiation are well understood.
Macrophages and neutrophils orchestrate the inflammatory response, communicating with each other and with T and B cells to induce cell activation and cell proliferation, to recruit more inflammatory cells, to kill the invader, to protect the surrounding tissue, to induce longer-term protective immunity, and to down regulate the response once the microorganism has been eliminated. These same processes can become chronically activated, leading to a variety of human diseases, such as autoimmune disease, multiple sclerosis, liver cirrhosis, arthritis, atherosclerosis, vascular disease, and even cancer. Academic and industrial concerns have large research programs devoted to understanding processes of inflammation that arises from various insults. Determining how microorganisms evade the immune system (immune evasion) can lead to the development of microbial-specific inhibitors. Determining how innate immune cells (macrophage/dendritic cells and neutrophils) mount an immune attack to different microbes can lead to the development of drugs that promote specific responses. Characterizing how specific microbes, such as HIV, live within macrophage/dendritic cells and respond to drugs within that context can identify new therapeutic avenues. And finally, inhibiting inflammatory responses that cause the devastating non-microbial human diseases (listed above) comprises a vast potential to relieve human suffering and generate highly profitable drugs.
Research within this field is expensive and time-consuming. Because macrophage/dendritic cells and neutrophils are non-mitotic, they need to be derived from large numbers of mice when laboratories are knocking out a single gene to look at the effect. If the knockout is embryonic lethal, day 13 or 14 mice can still be used as a sources of these cells, but the labor, time, and costs increase if cells are derived from such embryos. Once a knockout mouse has been derived for a specific protein, the goal of characterizing the specific domains of the protein that are important for its function are difficult because one can not restore production of the protein, or specific mutants of the protein, within mature inflammatory cells.